Multicomponent system which can be hardened by means of heat and actinic radiation, and use of the same

ABSTRACT

A multicomponent system curable thermally and with actinic radiation (dual cure), comprising
         (A) at least one component comprising at least one constituent containing at least one isocyanate-reactive functional group and at least one functional group having at least one bond which can be activated with actinic radiation, and at least one vinylaromatic-allyl alcohol copolymer, and   (B) at least one component comprising at least one polyisocyanate,
 
and its use as a coating material, adhesive and sealing compound.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Phase Application of Patent ApplicationPCT/EP01/11104 filed on 26 Sep. 2001, which claims priority to 100 48275.9, filed on 29 Sep. 2000.

The present invention relates to a novel multicomponent system curablethermally and with actinic radiation. The present invention also relatesto the use of the novel multicomponent system as a coating material,adhesive or sealing compound. The present invention further relates tothe use of the novel coating materials for automotive OEM finishing,automotive refinishing, the coating of furniture, doors, windows orconstructions in the interior and exterior sector, and also forindustrial coating, including coil coating, container coating and thecoating or impregnation of electrical components.

Here and below, actinic radiation is electromagnetic radiation such asnear infrared (NIR), visible light, UV radiation or X-rays, especiallyUV radiation, or corpuscular radiation such as electron beams.

Among those in the art, curing with heat and actinic radiation is alsoreferred to for short as dual cure.

A dual-cure multicomponent system is known, for example, from EuropeanPatent Application EP 0 928 800 A1. It comprises a urethane(meth)acrylate containing free isocyanate groups and (meth)acryloylgroups, a photoinitiator and an isocyanate-reactive compound, especiallya polyol or polyamine. Although this dual-cure coating material offersthe possibility of varying the profiles of properties of coatingmaterial and coating and of tailoring them to different end uses, itsflash-off time is still too long and its initial hardness in the shadowzones of three-dimensional substrates complex in shape, which are notreached by the actinic radiation without the use of relatively complexapparatus, is too low.

Moreover, such dual-cure multicomponent systems are known, alongsidemany other dual-cure multicomponent and one-component systems not basedon polyisocyanates, from German Patent Application DE 198 18 735 A1.

The advantages set out in the patent application, which are purportedlypossessed by all of the systems described therein, however, stop atgeneral indications and are not reinforced by a specific example.

It is an object of the present invention to find a new dual-curemulticomponent system which no longer has the disadvantages of the priorart but instead has a short flash-off time. Moreover, the coatingsproduced using it should have a high initial hardness, even in theproblematic shadow zones of three-dimensional substrates complex inshape.

Moreover, the novel dual-cure multicomponent system should be suitablenot only as a coating material but also as an adhesive and sealingcompound. Furthermore, the novel coating material should beoutstandingly suitable for automotive OEM finishing, automotiverefinishing, the coating of furniture, doors, windows or constructionsin the interior and exterior sector, and also for industrial coating,including coil coating, container coating and the coating orimpregnation of electrical components.

The intention is that the coatings, adhesive films and seals producedfrom the novel dual-cure multicoat system should exhibit high scratchresistance and very good chemical, gasoline, solvent and etch resistanceand weathering stability, and no cracks.

The adhesive films and seals should also exhibit a durable bond strengthor, respectively, a durable sealing ability even under extreme and/orrapidly changing climatic conditions.

The coatings should also be outstandingly suitable as clearcoats as partof multicoat color and/or effect coating systems. The novel clearcoatsshould have a high initial hardness, even in the problematic shadowregions of three-dimensional substrates complex in shape.

Accordingly, we have found the novel multicomponent system curablethermally and with actinic radiation (dual cure), comprising

-   (A) at least one component comprising at least one constituent    containing at least one isocyanate-reactive functional group and at    least one functional group having at least one bond which can be    activated with actinic radiation, and at least one additive, and-   (B) at least one component comprising at least one polyisocyanate,    said additive comprising at least one vinylaromatic-allyl alcohol    copolymer.

In the text below, the novel multicomponent system which is curablethermally and with actinic radiation is referred to as the“multicomponent system of the invention”.

The constituent of the multicomponent system of the invention that isessential to the invention is the vinylaromatic-allyl alcohol copolymer.

Suitable vinylaromatics per se are all substituted and unsubstitutedaromatics containing vinyl groups. Examples of suitable vinylaromaticsare styrene, alpha-methylstyrene, vinyltoluene, p-tert-butylstyrene orp-methyl-alpha-methylstyrene, but especially styrene.

The ratio of vinylaromatic to allyl alcohol in the copolymers may varywidely. The amount of allyl alcohol, based on the overall amount of thecopolymer, is preferably from 10 to 50, in particular from 15 to 45% byweight, and the amount of vinylaromatic, based on the overall amount ofthe copolymer, is preferably from 50 to 90, in particular from 55 to 85%by weight.

The number-average molecular weight of the copolymers may also vary. Itis preferably from 1000 to 4000, more preferably from 1200 to 3800, andin particular from 2500 to 3700 daltons.

The mass-average molecular weight is preferably from 2000 to 10 000,more preferably from 2300 to 9500, in particular from 2400 to 9300daltons.

The copolymer preferably has a hydroxyl number of from 80 to 300, inparticular from 110 to 270 mg KOH/g.

The glass transition temperature of the copolymer is preferably from 50to 90, in particular from 55 to 85° C.

Based on its solids content, the multicomponent system of the inventioncomprises the vinylaromatic-allyl alcohol copolymer preferably in anamount of from 1 to 30% by weight. In special cases it is also possibleto use higher amounts of copolymer. Preferably, the copolymer is used inan amount of from 2 to 27, in particular from 3 to 25% by weight, basedin each case on the solids content of the multicomponent system of theinvention.

The vinylaromatic-allyl alcohol copolymers for use in accordance withthe invention are compounds which are known per se and are sold, forexample, under the designation SAA-100, SAA-101 or SAA-103 by LyondellChem Nederland Ltd., Antwerp, Belgium.

As an additive containing isocyanate-reactive functional groups, thevinylaromatic-allyl alcohol copolymer is present in component (A) of themulticomponent system of the invention.

Component (A) comprises at least one constituent containing on averageat least one, especially two, isocyanate-reactive functional group(s)and at least one, especially two, functional group(s) containing permolecule on average at least one, especially one bond which can beactivated with actinic radiation.

Examples of suitable isocyanate-reactive functional groups are thiolgroups, primary and secondary amino groups, primary imino groups orhydroxyl groups, of which the primary and secondary amino groups and thehydroxyl group are of advantage and the hydroxyl groups are ofparticular advantage and are therefore used with particular preferencein accordance with the invention.

The constituent preferably has a hydroxyl number of from 50 to 200,preferably from 80 to 170, and in particular from 90 to 150 mg/KOH/g.

Examples of suitable bonds which can be activated with actinic radiationare carbon-hydrogen single bonds or carbon-carbon, carbon-oxygen,carbon-nitrogen, carbon-phosphorus or carbon-silicon single bonds ordouble bonds. Of these, the double bonds, especially the carbon-carbondouble bonds (“double bonds”), are employed with preference.

Very suitable double bonds are present, for example, in (meth)acrylate,ethacrylate, crotonate, cinnamate, vinyl ether, vinyl ester,ethenylarylene, dicyclopentadienyl, norbornenyl, isoprenyl, isopropenyl,allyl or butenyl groups; ethenylarylene ether, dicyclopentadienyl ether,norbornenyl ether, isoprenyl ether, isopropenyl ether, allyl ether orbutenyl ether groups; or ethenylarylene ester, dicyclopentadienyl ester,norbornenyl ester, isoprenyl ester, isopropenyl ester, allyl ester orbutenyl ester groups. Of these, (meth)acrylate groups, especiallyacrylate groups, are of particular advantage and are therefore used withvery particular preference in accordance with the invention.

The constituent may be of low molecular mass, oligomeric or polymeric.Preferably it is oligomeric or polymeric.

The double bonds may be present as terminal and/or lateral double bondsin the constituent.

The basic structures of the low molecular mass constituents are notcritical but instead may derive from any of a very wide variety oforganic compound classes. Examples of suitable classes of compound arealkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl,cycloalkylaryl, arylalkyl and/or arylcycloalkyl compounds with orwithout heteroatoms such as oxygen, nitrogen, sulfur, silicon orphosphorus and optionally carrying further substituents which, however,must not react during the preparation of the constituents, their storageand/or their use with the bonds which can be activated with actinicradiation.

The basic structures of the oligomeric or polymeric constituents arelikewise not critical and may derive from any of a wide variety ofoligomer and polymer classes. Examples of suitable oligomer and polymerclasses are random, alternating and/or block, linear and/or branchedand/or comb addition (co)polymers of ethylenically unsaturated monomers,or polyaddition resins and/or polycondensation resins. Regarding theseterms, reference is made for further details to Römpp Lexikon Lacke undDruckfarben, Georg Thieme Verlag, Stuttgart, N.Y., 1998, page 457,“Polyaddition” and “Polyaddition resins (polyadducts)”, and also pages463 and 464, “Polycondensates”, “Polycondensation” and “Polycondensationresins”. As regards any substituents which may be present, the remarksmade above apply accordingly.

Examples of highly suitable addition (co)polymers arepoly(meth)acrylates and partially hydrolyzed polyvinyl esters.

Examples of highly suitable polyaddition resins and/or polycondensationresins are polyesters, alkyds, polyurethanes, polylactones,polycarbonates, polyethers, epoxy resin-amine adducts, polyureas,polyamides or polyimides.

In accordance with the invention, the polyurethanes have particularadvantages and are therefore used with particular preference.

The preparation of polyurethanes having terminal and/or lateral doublebonds has no special features in terms of its method, instead beingdescribed in detail in patent applications and patents DE 196 45 761 A,WO 98/10028, EP 0 742 239 A1, EP 0 661 321 B, EP 0 608 021 B1, EP 0 447998 B1 or EP 0 462 287 B1. Moreover, these constituents are commerciallycustomary products and are sold, for example, under the brand name Rahn®99–664 by the Rahn company.

The amount of the above-described constituent in the multicomponentsystem of the invention may vary widely. Preferably it is from 20 to 60,more preferably from 25 to 55, and in particular from 30 to 50% byweight, based in each case on the solids content of the multicomponentsystem of the invention.

Component (A) of the multicomponent system of the invention may furthercomprise at least one constituent curable by means of heat alone,containing on average at least two isocyanate-reactive functional groupsper molecule. Examples of suitable isocyanate-reactive functional groupsare those described above. Preference is given to the use of hydroxylgroups.

The constituents curable by means of heat alone preferably compriseoligomeric or polymeric resins, as are normally used in multicomponentsystems. Their hydroxyl number is preferably from 70 to 200, morepreferably from 80 to 170, and in particular from 90 to 150 mg KOH/g.

As oligomers and polymers, the basic structures described above aresuitable, provided they contain no functional groups having bonds whichcan be activated with actinic radiation. In this context (meth)acrylatecopolymers have particular advantages and therefore are used withparticular preference.

The (meth)acrylate copolymers are polymers which are known per se. Theirpreparation has no special features as to method but instead takes placewith the aid of the methods—customary and known in the plastics field—ofcontinuous or batchwise free-radically initiated copolymerization inbulk, solution, emulsion, miniemulsion or microemulsion underatmospheric pressure or superatmospheric pressure in stirred vessels,autoclaves, tube reactors, loop reactors or Taylor reactors attemperatures from 50 to 200° C.

Examples of suitable (meth)acrylate copolymers and copolymerizationmethods are described in patent applications DE 197 09 465 A1, DE 197 09476 A1, DE 28 48 906 A1, DE 195 24 182 A1, DE 198 28 742 A1, DE 196 28143 A1, DE 196 28 142 A1, EP 0 554 783 A1, WO 95/27742, WO 82/02387 andWO 98/02466.

Where used, the amount of the (meth)acrylate copolymers in themulticomponent systems of the invention may vary widely. It ispreferably from 1 to 30, more preferably from 3 to 20, and in particularfrom 5 to 15% by weight, based in each case on the solids content of themulticomponent system of the invention.

Furthermore, component (A) of the multi-component system of theinvention may further comprise additional customary and known additivesin effective amounts. The essential factor is that the additives do notinhibit or entirely prevent the dual-cure crosslinking reactions.

Examples of suitable additives are nanoparticles, reactive diluentscurable thermally and/or with actinic radiation, low-boiling organicsolvents and high-boiling organic solvents (“long solvents”), water, UVabsorbers, light stabilizers, free-radical scavengers, thermally labilefree-radical initiators, photoinitiators and photocoinitiators,crosslinking agents as used in one-component systems, thermalcrosslinking catalysts, devolatilizers, slip additives, polymerizationinhibitors, defoamers, emulsifiers, wetting agents, dispersants,adhesion promoters, leveling agents, film-forming auxiliaries, sagcontrol agents (SCAs), rheology control additives (thickeners), flameretardants, siccatives, dryers, antiskinning agents, corrosioninhibitors, waxes, flatting agents, precursors of organically modifiedceramic materials, or additional binders.

Examples of suitable thermally curable reactive diluents arepositionally isomeric diethyloctanediols or hydroxyl-containinghyperbranched compounds or dendrimers, as described for example inGerman Patent Applications DE 198 05 421 A1, DE 198 09 643 A1, and DE198 40 405 A1.

Examples of suitable reactive diluents curable with actinic radiationare those described in Römpp Lexikon Lacke und Druckfarben, Georg ThiemeVerlag, Stuttgart, New York, 1998, on page 491 under the entry “Reactivediluents”.

Examples of suitable low-boiling organic solvents and high-boilingorganic solvents (“long solvents”) are ketones such as methyl ethylketone, methyl isoamyl ketone or methyl isobutyl ketone, esters such asethyl acetate, butyl acetate, ethyl ethoxypropionate, methoxypropylacetate or butyl glycol acetate, ethers such as dibutyl ether orethylene glycol, diethylene glycol, propylene glycol, dipropyleneglycol, butylene glycol or dibutylene glycol dimethyl, diethyl ordibutyl ether, N-methylpyrrolidone or xylenes or mixtures of aromaticand/or aliphatic hydrocarbons such as Solventnaphtha®, mineral spirit135/180, dipentenes or Solvesso®.

Examples of suitable thermally labile free-radical initiators areorganic peroxides, organic azo compounds or C—C-cleaving initiators suchas dialkyl peroxides, peroxocarboxylic acids, peroxodicarbonates, orperoxide esters, hydroperoxides, ketone peroxides, azo dinitriles orbenzpinacol silyl ethers.

Examples of suitable crosslinking catalysts are dibutyltin dilaurate,dibutyltin dioleate, lithium decanoate, zinc octoate or bismuth saltssuch as bismuth lactate or bismuth dimethylolpropionate.

Examples of suitable photoinitiators and coinitiators are described inRömpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart,1998, pages 444 to 446.

Examples of suitable additional crosslinking agents as used inone-component systems are amino resins, as described for example inRömpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, 1998, page 29,“Amino resins”, in the textbook “Lackadditive” [Additives for Coatings]by Johan Bieleman, Wiley-VCH, Weinheim, N.Y., 1998, pages 242 ff., inthe book “Paints, Coatings and Solvents”, second, completely revisededition, D. Stoye and W. Freitag (eds.), Wiley-VCH, Weinheim, N.Y.,1998, pages 80 ff., in patents U.S. Pat. No. 4,710,542 A1 and EP-B-0 245700 A1, and in the article by B. Singh and coworkers,“Carbamylmethylated Melamines, Novel Crosslinkers for the CoatingsIndustry”, in Advanced Organic Coatings Science and Technology Series,1991, Volume 13, pages 193 to 207; carboxyl-containing compounds orresins, as described for example in patent DE 196 52 813 A1; compoundsor resins containing epoxide groups, as described for example in patentsEP 0 299 420 A1, DE 22 14 650 B1, DE 27 49 576 B1, U.S. Pat. No.4,091,048 A and U.S. Pat. No. 3,781,379 A; blocked polyisocyanates, asdescribed for example in patents U.S. Pat. No. 4,444,954 A, DE 196 17086 A1, DE 196 31 269 A1, EP 0 004 571 A1 and EP 0 582 051 A1; and/ortris(alkoxycarbonylamino)triazines as described in patents U.S. Pat. No.4,939,213 A, U.S. Pat. No. 5,084,541 A, U.S. Pat. No. 5,288,865 A and EP0 604 922 A1.

Examples of suitable devolatilizers are diazadicycloundecane andbenzoin.

Examples of suitable emulsifiers are nonionic emulsifiers, such asalkoxylated alkanols, polyols, phenols and alkylphenols, or anionicemulsifiers such as alkali metal salts or ammonium salts ofalkanecarboxylic acids, alkanesulfonic acids, and sulfo acids ofalkoxylated alkanols, polyols, phenols and alkylphenols.

Examples of suitable wetting agents are siloxanes, fluorine compounds,carboxylic monoesters, phosphoric esters, polyacrylic acids and theircopolymers, or polyurethanes.

An example of a suitable adhesion promoter is tricyclodecanedimethanol.

Examples of suitable film-forming auxiliaries are cellulose derivativessuch as cellulose acetobutyrate (CAB).

Examples of suitable transparent fillers are those based on silicondioxide, aluminum oxide or zirconium oxide; for further details,reference is made to Römpp Lexikon Lacke und Druckfarben, Georg ThiemeVerlag, Stuttgart, 1998, pages 250 to 252.

Examples of suitable sag control agents are ureas, modified ureas and/orsilicas, as described for example in the literature references EP 0 192304 A1, DE 23 59 923 A1, DE 18 05 693 A1, WO 94/22968, DE 27 51 761 C1,WO 97/12945 or “farbe+lack”, 11/1992, pages 829 ff.

Examples of suitable rheology control additives are those known frompatents WO 94/22968, EP 0 276 501 A1, EP 0 249 201 A1 and WO 97/12945;crosslinked polymeric microparticles, as disclosed for example in EP 0008 127 A1; inorganic phyllosilicates such as aluminum-magnesiumsilicates, sodium-magnesium and sodium-magnesium-fluorine-lithiumphyllosilicates of the montmorillonite type; silicas such as Aerosils;or synthetic polymers containing ionic and/or associative groups such aspolyvinyl alcohol, poly-(meth)acrylamide, poly(meth)acrylic acid,polyvinyl-pyrrolidone, styrene-maleic anhydride copolymers orethylene-maleic anhydride copolymers and their derivatives orhydrophobically modified ethoxylated urethanes or polyacrylates.

An example of a suitable flatting agent is magnesium stearate.

Examples of suitable precursors of organically modified ceramicmaterials are hydrolyzable organometallic compounds, especially ofsilicon and aluminum.

Further examples of the above-listed additives and also examples ofsuitable UV absorbers, free-radical scavengers, leveling agents, flameretardants, siccatives, dryers, antiskinning agents, corrosioninhibitors and waxes (B) are described in detail in the textbook“Lackadditive” [Additives for coatings] by Johan Bieleman, Wiley-VCH,Weinheim, N.Y., 1998.

The preparation of component (A) for use in accordance with theinvention has no special features but instead takes place in a customaryand known manner by mixing of the above-described constituents inappropriate mixing equipment such as stirred vessels, dissolvers,stirred mills or extruders.

Component (B) of the multicomponent system of the invention comprises atleast one polyisocyanate.

The polyisocyanates contain on average at least 2.0, preferably morethan 2.0, and in particular more than 3.0 isocyanate groups permolecule. Basically, there is no upper limit on the number of isocyanategroups; in accordance with the invention, however, it is of advantage ifthe number does not exceed 15, preferably 12, with particular preference10, with very particular preference 8.0, and in particular 6.0.

Examples of suitable polyisocyanates are isocyanato-containingpolyurethane prepolymers which may be prepared by reacting polyols withan excess of diisocyanates and are preferably of low viscosity.

Examples of suitable diisocyanates are isophorone diisocyanate (i.e.,5-isocyanato-1-iso-cyanatomethyl-1,3,3-trimethylcyclohexane),5-iso-cyanato-1-(2-isocyanatoeth-1-yl)-1,3,3-trimethylcyclo-hexane,5-isocyanato-1-(3-isocyanatoprop-1-yl)-1,3,3-trimethylcyclohexane,5-isocyanato-(4-isocyanatobut-1-yl)-1,3,3-trimethylcyclohexane,1-isocyanato-2-(3-iso-cyanatoprop-1-yl)-cyclohexane,1-isocyanato-2-(3-iso-cyanatoeth-1-yl)cyclohexane,1-isocyanato-2-(4-iso-cyanatobut-1-yl)-cyclohexane,1,2-diisocyanatocyclo-butane, 1,3-diisocyanatocyclobutane,1,2-diisocyanato-cyclopentane, 1,3-diisocyanatocyclopentane,1,2-diiso-cyanatocyclohexane, 1,3-diisocyanatocyclohexane,1,4-diisocyanatocyclohexane, dicyclohexylmethane 2,4′-diisocyanate,trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylenediisocyanate, hexa-methylene diisocyanate (HDI), ethylethylenediiso-cyanate, trimethylhexane diisocyanate, heptamethylene diisocyanateor diisocyanates derived from dimeric fatty acids, as sold under thecommercial designation DDI 1410 by the company Henkel and described inpatents WO 97/49745 and WO 97/49747, especially2-heptyl-3,4-bis(9-isocyanatononyl)-1-pentylcyclohexane, or 1,2-, 1,4-or 1,3-bis(isocyanatomethyl)cyclohexane, 1,2-, 1,4- or1,3-bis(2-isocyanatoeth-1-yl)cyclohexane,1,3-bis(3-isocyanatopropy-1-yl)cyclohexane, 1,2-, 1,4- or1,3-bis(4-isocyanatobut-1-yl)cyclohexane or liquidbis(4-isocyanatocyclohexyl)methane with a trans/trans content of up to30% by weight, preferably 25% by weight and in particular 20% by weight,as described in patent applications DE 44 14 032 A1, GB 1220717 A1, DE16 18 795 A1 and DE 17 93 785 A1, preferably isophorone diisocyanate,5-isocyanato-1-(2-iso-cyanatoeth-1-yl)-1,3,3-trimethylcyclohexane,5-iso-cyanato-1-(3-isocyanatoprop-1-yl)-1,3,3-trimethylcyclo-hexane,5-isocyanato-(4-isocyanatobut-1-yl)-1,3,3-tri-methylcyclohexane,1-isocyanato-2-(3-isocyanatoprop-1-yl)cyclohexane,1-isocyanato-2-(3-isocyanatoeth-1-yl)-cyclohexane,1-isocyanato-2-(4-isocyanatobut-1-yl)-cyclohexane or HDI, especiallyHDI.

It is also possible to use polyisocyanates containing isocyanurate,biuret, allophanate, iminooxadiazinedione, urethane, urea, carbodiimideand/or uretdione groups, which are prepared in a customary and knownmanner from the diisocyanates described above. Examples of suitablepreparation techniques and polyisocyanates are known, for example, frompatents CA 2,163,591 A, U.S. Pat. No. 4,419,513, U.S. Pat. No. 4,454,317A, EP 0 646 608 A, U.S. Pat. No. 4,801,675 A, EP 0 183 976 A1, DE 40 15155 A1, EP 0 303 150 A1, EP 0 496 208 A1, EP 0 524 500 A1, EP 0 566 037A1, U.S. Pat. No. 5,258,482 A1, U.S. Pat. No. 5,290,902 A1, EP 0 649 806A1, DE 42 29 183 A1 and EP 0 531 820 A1.

The amount of the polyisocyanates in the multicomponent systems of theinvention may vary widely and is guided primarily by their functionalityand by the functionality of the constituents present in component (A)that contain isocyanate-reactive groups. However, it may also be guidedby whether there are still constituents containing at least oneisocyanate group and at least one functional group having at least onebond which can be activated with actinic radiation in component (B).Preferably, the polyisocyanates are present in the multicomponentsystems of the invention in an amount of from 10 to 70, more preferablyfrom 15 to 65, and in particular from 20 to 60% by weight, based in eachcase on the solids content of the multicomponent system of theinvention.

Component (B) may also comprise at least one constituent containing atleast one isocyanate group and at least one functional group containingat least one bond which can be activated with actinic radiation. Theseconstituents, as is known, are obtainable by reacting theabove-described diisocyanates and polyisocyanates with compoundscontaining at least one, especially one, of the above-describedisocyanate-reactive functional groups and at least one, especially one,bond which can be activated with actinic radiation. Examples of suitablecompounds of this kind are

-   2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 3-hydroxybutyl,    4-hydroxybutyl, bis(hydroxymethyl)-cyclohexane, neopentyl glycol,    diethylene glycol, dipropylene glycol, dibutylene glycol, and    triethylene glycol acrylate, methacrylate, ethacrylate, crotonate,    cinnamate, vinyl ether, allyl ether, dicyclopentadienyl ether,    norbornenyl ether, isoprenyl ether, isopropenyl ether or butenyl    ether;-   trimethylolpropane di-, glycerol di-, trimethylolethane di-,    pentaerythritol tri- or homo-pentaerythritol tri-acrylate,    -methacrylate, -ethacrylate, -crotonate, -cinnamate, -vinyl ether,    -allyl ether, -dicyclopentadienyl ether, -norbornenyl ether,    -isoprenyl ether, -isopropyl ether or -butenyl ether; or-   reaction products of cyclic esters, such as epsilon-caprolactone,    for example, and the above-described hydroxyl-containing monomers;    or-   2-aminoethyl (meth)acrylate and/or 3-aminopropyl (meth)acrylate.

In terms of method, the preparation of these constituents has no specialfeatures but instead takes place as described, for example, in EuropeanPatent Application EP 0 928 800 A1.

Where used, the amount of the constituent containing at least oneisocyanate group and at least one functional group containing at leastone bond which can be activated by actinic radiation may vary widely.Preferably, the amount is from 5 to 40, more preferably from 10 to 35,in particular from 15 to 30% by weight, based in each case on the solidscontent of the multicomponent system of the invention.

Preparation of component (B) has no special features in terms of methodeither but instead takes place by mixing its constituents. In order toestablish a low viscosity, component (B) may further be admixed with atleast one of the above-described organic solvents.

Where the multicomponent system of the invention comprises onlycomponents (A) and (B), it constitutes a two-component system. However,different constituents of the individual components (A) and/or (B) maybe stored separately from these components and not combined untilshortly before application to form the multicomponent system. Ingeneral, the two-component system is preferred since it entails lesseffort for its preparation.

The preparation of the multicomponent systems of the invention from theabove-described components has no special features in terms of itsmethod but instead is carried out with the aid of the customary andknown, above-described mixing equipment and mixing techniques or bymeans of customary two-component or multicomponent metering and mixingunits. Ideally, mixing takes place by hand.

The multicomponent systems of the invention may be put to a very widevariety of end uses. Preferably, they are used as coating materials,adhesives and sealing compounds.

The coating materials, adhesives and sealing compounds of the inventionare used to produce coatings, adhesive films and seals on and/or inprimed and unprimed substrates. In particular, the coating materials ofthe invention are used to produce clearcoats, especially clearcoats inmulticoat color and/or effect coating systems.

In terms of method, the application of the clearcoat materials of theinvention has no special features but instead may take place by anycustomary application method, such as spraying, knifecoating, brushing,flowcoating, dipping, trickling or rolling, for example. It is preferredto employ spray application methods, such as compressed air spraying,airless spraying, high-speed rotation, electrostatic spray application(ESTA), alone or in conjunction with hot spray applications such ashot-air spraying, for example.

Suitable substrates are surfaces which are not damaged by curing of thecoating materials, adhesives and/or sealing compounds present thereonusing heat and actinic radiation; examples are metals, plastics, wood,ceramic, stone, textile, fiber composites, leather, glass, glass fibers,glass wool, rockwool, mineral-bound and resin-bound building materials,such as plasterboard and cement slabs or roof tiles, and also assembliesof these materials.

Accordingly, the coating materials, adhesives and sealing compounds ofthe invention are also suitable for applications outside of automotiveOEM finishing and automotive refinishing. In this context they areparticularly suitable for the coating, bonding and/or sealing offurniture, windows, doors, constructions in the interior and exteriorsector, and for industrial coating, including coil coating, containercoating and the impregnation or coating of electrical components. In thecontext of industrial coatings, they are suitable for coating, bondingand/or sealing virtually all parts for private or industrial use, suchas radiators, domestic appliances, small metal parts such as nuts andbolts, hub caps, wheel rims, packaging, or electrical components such asmotor windings or transformer windings.

In the case of electrically conductive substrates, it is possible to useprimers which are produced in a customary and known manner from theelectrodeposition coating materials. Both anodic and cathodicelectrodeposition coating materials are suitable for this purpose, butespecially cathodic materials.

The electrodeposition coat or electrodeposition coating film may beovercoated with a surfacer, which is cured either alone or together withthe electrodeposition coating film (wet-on-wet process). Overcoatingwith a surfacer takes place in particular in those regions exposed tosevere mechanical stress, such as by stone chipping, for example.

Examples of suitable cathodic electodeposition coating materials and,where appropriate, of wet-on-wet processes are described in JapanesePatent Application 1975-142501 (Japanese Laid-open Specification JP52-065534 A2, Chemical Abstracts No. 87: 137427) or in patents andpatent applications U.S. Pat. No. 4,375,498 A, U.S. Pat. No. 4,537,926A, U.S. Pat. No. 4,761,212 A, EP 0 529 335 A1, DE 41 25 459 A1, EP 0 595186 A1, EP 0 074 634 A1, EP 0 505 445 A1, DE 42 35 778 A1, EP 0 646 420A1, EP 0 639 660 A1, EP 0 817 648 1A, DE 195 12 017 C1, EP 0 192 113 A2,DE 41 26 476 A1 or WO 98/07794.

Similarly, appropriate surfacers, especially aqueous surfacers, whichare also referred to as antistonechip primers or functional coats, areknown from patents and patent applications U.S. Pat. No. 4,537,926 A, EP0 529 335 A1, EP 0 595 186 A1, EP 0 639 660 A1, DE 44 38 504 A1, DE 4337 961 A1, WO 89/10387, U.S. Pat. No. 4,450,200 A, U.S. Pat. No.4,614,683 A or WO 94/26827.

It is also possible to coat, bond or seal primed or unprimed plasticsparts made, for example, from ABS, AMMA, ASA, CA, CAB, EP, UF, CF, MF,MPF, PF, PAN, PA, PE, HDPE, LDPE, LLDPE, UHMWPE, PC, PC/PBT, PC/PA, PET,PMMA, PP, PS, SB, PUR, PVC, RF, SAN, PBT, PPE, POM, PUR-RIM, SMC, BMC,PP-EPDM and UP (abbreviated codes in accordance with DIN 7728T1).Unfunctionalized and/or nonpolar substrate surfaces may be subjectedprior to coating in a known manner to a pretreatment, such as by plasmaor by flaming, or may be provided with a primer.

In accordance with the invention, to produce the clearcoats of theinvention, the clearcoat materials of the invention are applied to thesubstrates described above, after which the resulting clearcoat filmsare cured.

In accordance with the invention, to produce the adhesive films andseals of the invention, the adhesives and sealing compounds of theinvention are applied on and/or in the substrates described above. Forthe adhesive bonding of substrates, the surfaces of two or moresubstrates that are to be bonded are preferably coated with the adhesiveof the invention, after which the surfaces in question are contacted,under pressure if appropriate, and the resulting adhesive films arecured.

As is known, the production of a multicoat color and/or effect coatingsystem on a primed or unprimed substrate takes place by

-   (1) applying a basecoat material to the substrate,-   (2) drying and/or partly curing or fully curing the basecoat film,-   (3) applying a clearcoat material to the dried and/or partly cured    basecoat film or to the cured basecoat, and-   (4) conjointly curing the clearcoat film with the basecoat film, or    separately curing the clearcoat film.

Examples of suitable basecoat materials are known from patentapplications EP 0 089 497 A1, EP 0 256 540 A1, EP 0 260 447 A1, EP 0 297576 A1, WO 96/12747, EP 0 523 610 A1, EP 0 228 003 A1, EP 0 397 806 A1,EP 0 574 417 A1, EP 0 531 510 A1, EP 0 581 211 A1, EP 0 708 788 A1, EP 0593 454 A1, DE-A-43 28 092 A1, EP 0 299 148 A1, EP 0 394 737 A1, EP 0590 484 A1, EP 0 234 362 A1, EP 0 234 361 A1, EP 0 543 817 A1, WO95/14721, EP 0 521 928 A1, EP 0 522 420 A1, EP 0 522 419 A1, EP 0 649865 A1, EP 0 536 712 A1, EP 0 596 460 A1, EP 0 596 461 A1, EP 0 584 818A1, EP 0 669 356 A1, EP 0 634 431 A1, EP 0 678 536 A1, EP 0 354 261 A1,EP 0 424 705 A1, WO 97/49745, WO 97/49747, EP 0 401 565 A1, and EP 0 817684, column 5, lines 31 to 45.

In general, the surfacer film, topcoat film, basecoat film and clearcoatfilm are applied in a wet film thickness such that curing thereofresults in coats having the film thicknesses necessary and advantageousfor their functions. In the case of the surfacer film this filmthickness is from 10 to 150, preferably from 15 to 120, with particularpreference from 20 to 100, and in particular from 25 to 90 μm, in thecase of the topcoat the film thickness is from 5 to 90, preferably from10 to 80, with particular preference from 15 to 60, and in particularfrom 20 to 50 μm, in the case of the basecoat from 5 to 50, preferablyfrom 6 to 40, with particular preference from 7 to 30, and in particularfrom 8 to 25 μm and in the case of the clearcoats it is from 10 to 100,preferably from 15 to 90, with particular preference from 20 to 80, andin particular from 25 to 70 μm.

The complete curing may take place after a certain flash-off time. Thisis used, for example, for leveling and for the degassing of the appliedfilms or for the evaporation of volatile constituents such as solventsor water. The resting time may be assisted and/or shortened by the useof elevated temperatures up to 40° C. and/or by blowing, provided thisdoes not entail any damage or alteration to the applied films, such aspremature complete crosslinking, for example. The clearcoats of theinvention have an advantageously short flash-off time of <10, especially<6 minutes. This produces a shortening in the process times overall.

In accordance with the invention, complete curing takes place withactinic radiation, especially with UV radiation, and/or electron beams.If desired, it may be carried out with or supplemented by actinicradiation from other radiation sources. In the case of electron beams,it is preferred to operate under an inert gas atmosphere. This may beensured, for example, by supplying carbon dioxide and/or nitrogendirectly to the surface of the applied films.

In the case of curing with UV radiation as well, it is possible tooperate under inert gas in order to prevent the formation of ozone.

Curing with actinic radiation is carried out using the customary andknown radiation sources and optical auxiliary measures. Examples ofsuitable radiation sources are high or low pressure mercury vapor lamps,with or without lead doping in order to open up a radiation window of upto 405 nm, or electron beam sources. Their arrangement is known inprinciple and may be adapted to the circumstances of the workpiece andthe process parameters. In the case of workpieces of complex shape suchas automobile bodies, the regions not accessible by direct radiation(shadow regions) such as cavities, folds and other structural undercutsmay be cured using point, small-area or all-round sources, inconjunction with an automatic movement device for the irradiation ofcavities or edges.

The equipment and conditions for these curing methods are described, forexample, in R. Holmes, U. V. and E. B. Curing Formulations for PrintingInks, Coatings and Paints, SITA Technology, Academic Press, London,United Kingdom 1984.

Curing may take place in stages, i.e., by multiple exposure to light oractinic radiation. This can also be done alternatingly, i.e., by curingin alternation with UV radiation and electron beams.

Thermal curing has no special features in terms of method either butinstead takes place in accordance with the customary and known methodssuch as heating in a forced air oven or irradiation with IR lamps. Asfor curing with actinic radiation, thermal curing may also take place instages. Thermal curing is preferably effected at room temperature orabove room temperature, preferably at temperatures >40° C.,preferably >50° C., for a period of from one minute to several days.

Thermal curing and curing with actinic radiation may be usedsimultaneously or in alternation. Where the two curing methods are usedin alternation, it is possible, for example, to commence with thermalcuring and end with actinic radiation curing. In other cases, it mayprove advantageous to commence and to end with actinic radiation curing.The skilled worker is able to determine the curing method which is mostadvantageous for the particular case in hand, on the basis of hisgeneral knowledge of the art with the assistance, if appropriate, ofsimple preliminary tests.

The coating materials, adhesives and sealing compounds of the inventionhave a high solids content at low viscosity and a long useful life.

The flash-off time of the multicomponent systems of the invention,especially of the clearcoat material of the invention, before curing isvery short, so that overall process times are reduced.

The coats, adhesive films and seals produced with the aid of themulticomponent systems of the invention, especially the clearcoats ofthe invention, have a high initial hardness even in the shadow regionsof the substrates.

The resultant coatings of the invention, especially the clearcoats andthe multicoat color and/or effect coating systems comprising them,possess high hardness, flexibility, and chemical resistance, outstandingleveling, no runs, very good intercoat adhesion, an outstanding overallappearance, very good weathering stability, very high scratch resistanceand abrasion resistance, and also very good polishability.

The adhesive films of the invention are of high and long-term bondstrength even under extreme and/or very severely and rapidly changingclimatic conditions.

The seals of the invention provide long-term, complete sealing withrespect to chemically aggressive substances.

Accordingly, the primed and unprimed substrates of the invention whichare coated with at least one coating of the invention, bonded with atleast one adhesive film of the invention and/or sealed with at least oneseal of the invention feature not only the advantages set out above butalso a particularly long service life, which makes them particularlyvaluable from an economic standpoint.

EXAMPLES Preparation Example 1 The Preparation of a Thermally CurableMethacrylate Copolymer

A steel reactor equipped with stirrer, reflux condenser and two feedvessels was charged with 185.6 parts by weight of ethyl epoxypropionateand this initial charge was heated with stirring to 160° C.Subsequently, a monomer mixture of 114.1 parts by weight of styrene,136.9 parts by weight of methyl methacrylate, 79.3 parts by weight ofbutyl methacrylate, 109 parts by weight of n-butyl acrylate and 164.1parts by weight of hydroxyethyl methacrylate was metered in at a uniformrate over the course of four hours. Beginning at the same time and inparallel with this monomer mixture, an initiator mixture of 35.8 partsby weight of ethyl ethoxypropionate and 36.2 parts by weight ofdi-tert-butyl peroxide was metered in at a uniform rate. After one hour,initiation was repeated at 110° C. with an initiator mixture of 5.7parts by weight of butyl acetate and 0.5 parts by weight of tert-butylperoxyethylhexanoate. Subsequently, the resultant reaction mixture washeld at 110° C. for one hour. Thereafter, at 80° C., the solution wasadjusted to a solids content of 65% by weight using butyl acetate. Theresultant solution had a viscosity of 15 dpas. The hydroxyl number ofthe methacrylate copolymer was 120 mg KOH/g.

Examples 1 and 2 The Preparation of Clearcoat Materials of the Inventionand Their Use to Produce Multicoat Color and Effect Coating Systems

The clearcoat materials 1 and 2 of the invention of Examples 1 and 2were prepared by mixing the constituents stated in Table 1. For thispurpose, components (A) and (B) were mixed with one another in a volumeratio of 2:1 and then diluted with 10%, based on the clearcoatmaterials, of a diluent (solvent mixture of xylene, solvent naphtha,mineral spirit 135/180, methoxypropyl acetate, butyl acetate, butylglycol acetate, ethyl ethoxypropionate and dipentenes).

TABLE 1 The material composition of clearcoat materials 1 and 2 of theinvention Constituent Example 1 Example 2 Component (A): Methacrylatecopolymer 16.5 16.5 of Preparation example 1 Urethaneacrylate^(a)) 40 40SAA 103^(b)) 10.5 10.5 Butyl acetate 14 14 Ethyl ethoxypropionate 10 10Methyl isoamyl ketone 4 4 Byk ® 325^(c)) 0.3 0.3 Byk ® 358^(c)) 0.7 0.7Tinuvin ® 292^(d)) 1 1 Tinuvin ® 400^(d)) 1 1 Irgacure ® 184^(e)) 1.11.1 Lucirin ® TPO^(e)) 0.4 0.4 Dibutyltin dilaurate 0.5 0.5 (10% inbutyl acetate) Component (B): Desmodur ® N 3600^(f)) 60 23 Roskydal ®2337^(g)) — 42 Methyl isoamyl ketone 20 20 ^(a))commercially customaryurethane acrylate Rahn ® 99–664 from Rahn; ^(b))commercially customarystyrene-allyl alcohol copolymer from Lyondell (hydroxyl number: 125 mgKOH/g; number-average molecular weight: 3200 daltons; mass-averagemolecular weight: 8400 daltons; glass transition temperature: 78° C.);^(c))commercially customary leveling agents; ^(d))commercially customarylight stabilizers; ^(e))commercially customary photoinitiators;^(f))commercially customary polyisocyanate based on hexamethylenediisocyanate, from Bayer AG; ^(g))commercially customary isocyanatoacrylate from Bayer AG.

The clearcoat materials 1 and 2 of the invention had a pot life of twohours.

To produce the multicoat color and effect coating systems, sanded steelpanels were first of all coated with a commercially customarytwo-component polyurethane surfacer from BASF Coatings AG. The surfacerwas applied in two spray passes, dried at 60° C. for 30 minutes and thensanded. Subsequently, an aqueous basecoat material was applied in twospray passes and dried at 60° C. for 5 minutes. Thereafter, theclearcoat materials of Examples 1 and 2 were each applied in two spraypasses with a flash-off time of 2.5 minutes in between.

The applied clearcoat films 1 and 2 were flashed off for 5 minutes,dried at 60° C. for 8 minutes, and then cured using UV radiation with adose of 1500 mJ/cm². The resultant clearcoats 1 and 2 had a filmthickness of from 50 to 60 μm. The appearance of the multicoat systemsof the invention from Examples 1 and 2 was outstanding.

To determine the initial hardness, the pendulum hardness of the appliedclearcoat films was measured in accordance with König (pendulum swings).The results are given in Table 2. They demonstrate the high initialhardness of the clearcoat films 1 and 2 and of the clearcoats 1 and 2.

In a second test series, the curing behavior of the clearcoat materials1 and 2 in shadow zones of substrates was simulated by not curing theabove-described test panels with UV radiation. Nevertheless, theresultant clearcoats 1 and 2 were not tacky but instead had a goodinitial hardness.

TABLE 2 Initial hardness of the clearcoat films and of the clearcoats 1and 2 Pendulum swings Curing conditions Example 1 Example 2 Test series1: Curing with UV radiation: after 4 hours 85 68 after 7 days 155 150Test series 2: Curing without UV radiation: after 4 hours 25 19 after 7days 79 72

1. A multicomponent system curable thermally and with actinic radiation,comprising (A) at least one component comprising at least oneconstituent comprising at least one isocyanate-reactive functional groupand at least one functional group comprising at least one bond activatedwith actinic radiation, and at least one additive comprising at leastone vinylaromatic-allyl alcohol copolymer, and (B) at least onecomponent comprising at least one polyisocyanate.
 2. The system of claim1, wherein the vinylaromatic-allyl alcohol copolymer, based on itsoverall amount, comprises from 10 to 50% by weight of allyl alcohol andfrom 50 to 90% by weight of a vinylaromatic monomer.
 3. The system ofclaim 1, wherein the vinylaromatic-allyl alcohol copolymer has anumber-average molecular weight of from 1000 to 4000 daltons and amass-average molecular weight of from 2000 to 10,000 daltons.
 4. Thesystem of claim 1, wherein the vinylaromatic-allyl alcohol copolymer hasa hydroxyl number of from 80 to 300 mg KOH/g.
 5. The system of claim 1,wherein the vinylaromatic-allyl alcohol copolymer has a glass transitiontemperature of from 50 to 90° C.
 6. The system of claim 1, comprising,from 1 to 30% by weight of the vinylaromatic-allyl alcohol copolymer,based on the solids content of the system.
 7. The system of claim 1,wherein component (B) further comprises at least one constituentcomprises at least one isocyanate group and at least one functionalgroup having at least one bond activated with actinic radiation.
 8. Thesystem of claim 1, wherein the bonds activated with actinic radiationare at least one bond selected from the group consisting ofcarbon-hydrogen single bonds, carbon-carbon single or double bonds,carbon-oxygen single or double bonds, carbon-nitrogen single or doublebonds, carbon-phosphorus single or double bonds, carbon-silicon singleor double bonds, and mixtures thereof.
 9. The system of claim 8, whereinthe bonds activated with actinic radiation are carbon-carbon doublebonds.
 10. The system of claim 1, wherein the at least one functionalgroup comprising at least one bond activated with actinic radiation is afunctional group selected from the group consisting of (meth)acrylate,ethacrylate, crotonate, cinnamate, vinyl ether, vinyl ester,ethenylarylene, dicyclopentadienyl, norbornenyl, isoprenyl, isopropenyl,allyl, butenyl, ethenylarylene ether, dicyclopentadienyl ether,norbornenyl ether, isoprenyl ether, isopropenyl ether, allyl ether,butenyl ether, ethenylarylene ester, dicyclopentadienyl ester,norbornenyl ester, isoprenyl ester, isopropenyl ester, allyl ester,butenyl ester, and mixtures thereof.
 11. The system of claim 1, whereinthe isocyanate-reactive functional groups are selected from the groupconsisting of thiol groups, primary amino groups, secondary aminogroups, imino groups, hydroxyl groups, and mixtures thereof.
 12. Thesystem of claim 1, wherein component (A) further comprises at least oneconstituent curable by means of heat alone, comprising at least twoisocyanate-reactive functional groups.
 13. A method of coating asubstrate, comprising applying the system of claim 1 to a substrate. 14.The method of claim 13 wherein the substrate is selected from the groupconsisting of automotive OEM substrates, automotive refinishingsubstrates, furniture substrates, doors, windows, interior and exteriorsector substrates, industrial coating substrates, coil coatingsubstrates, container coating substrates, electrical componentssubstrates, and mixtures thereof.
 15. The method of claim 13 wherein thesystem is applied by the wet-on-wet process.
 16. The system of claim 1wherein the vinylaromatic monomer is styrene.